don't try to send packets after closing the session

session.go

@@ -527,18 +527,21 @@ runLoop:
 			continue
 		}
 
-		if err := s.sendPackets(); err != nil {
-			s.closeLocal(err)
-		}
-
 		if !s.receivedTooManyUndecrytablePacketsTime.IsZero() && s.receivedTooManyUndecrytablePacketsTime.Add(protocol.PublicResetTimeout).Before(now) && len(s.undecryptablePackets) != 0 {
 			s.closeLocal(qerr.Error(qerr.DecryptionFailure, "too many undecryptable packets received"))
+			continue
 		}
 		if !s.handshakeComplete && now.Sub(s.sessionCreationTime) >= s.config.HandshakeTimeout {
 			s.closeLocal(qerr.Error(qerr.HandshakeTimeout, "Crypto handshake did not complete in time."))
+			continue
 		}
 		if s.handshakeComplete && now.Sub(s.lastNetworkActivityTime) >= s.config.IdleTimeout {
 			s.closeLocal(qerr.Error(qerr.NetworkIdleTimeout, "No recent network activity."))
+			continue
+		}
+
+		if err := s.sendPackets(); err != nil {
+			s.closeLocal(err)
 		}
 	}